package cn.openread.demo.nio.demo;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.InetSocketAddress;
import java.nio.ByteBuffer;
import java.nio.channels.SelectionKey;
import java.nio.channels.Selector;
import java.nio.channels.SocketChannel;
import java.util.Iterator;
import java.util.Set;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

public class NIOEchoClientHandler implements Runnable {

    private String host;
    private int port;

    private Selector selector;
    private SocketChannel socketChannel;

    private ExecutorService executorService;

    private volatile boolean stop;

    public NIOEchoClientHandler(String host, int port) {
        this.host = host == null ? "127.0.0.1" : host;
        this.port = port;
        this.executorService = Executors.newSingleThreadExecutor();

        try {
            selector = Selector.open();
            socketChannel = SocketChannel.open();
            socketChannel.configureBlocking(false);
        } catch (IOException e) {
            e.printStackTrace();
            System.exit(1);
        }
    }

    @Override
    public void run() {
        try {
            socketChannel.register(selector, SelectionKey.OP_CONNECT);
            socketChannel.connect(new InetSocketAddress(host, port));
        } catch (IOException e) {
            e.printStackTrace();
            System.exit(1);
        }
        while (!stop) {
            try {
                selector.select(1000);
                Set<SelectionKey> selectedKeys = selector.selectedKeys();
                Iterator<SelectionKey> it = selectedKeys.iterator();
                SelectionKey key = null;
                while (it.hasNext()) {
                    key = it.next();
                    it.remove();
                    try {
                        handleInput(key);
                    } catch (Exception e) {
                        if (key != null) {
                            key.cancel();
                            if (key.channel() != null)
                                key.channel().close();
                        }
                    }
                }
            } catch (Exception e) {
                e.printStackTrace();
                System.exit(1);
            }
        }

        // 多路复用器关闭后，所有注册在上面的Channel和Pipe等资源都会被自动去注册并关闭，所以不需要重复释放资源
        if (selector != null) {
            try {
                selector.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }

        if (executorService != null) {
            executorService.shutdown();
        }
    }

    private void handleInput(SelectionKey key) throws IOException {
        if (key.isValid()) {
            // 判断是否连接成功
            SocketChannel sc = (SocketChannel) key.channel();
            if (key.isConnectable()) {
                if (sc.finishConnect()) {
                    System.out.println("连接到服务器......");

                    ByteBuffer buffer = ByteBuffer.allocate(1024);
                    System.out.println("请输入消息[输入\"Quit\"]退出：");

                    executorService.submit(() -> {
                        while (true) {
                            try {
                                buffer.clear();
                                InputStreamReader input = new InputStreamReader(System.in);
                                BufferedReader br = new BufferedReader(input);

                                String msg = br.readLine();

                                if (msg.equals("Quit")) {
                                    System.out.println("关闭客户端......");
                                    key.cancel();
                                    sc.close();
                                    this.stop = true;
                                    break;
                                }

                                buffer.put(msg.getBytes());
                                buffer.flip();

                                sc.write(buffer);

                                System.out.println("请输入消息[输入\"Quit\"]退出：");

                            } catch (Exception ex) {
                                ex.printStackTrace();
                            }
                        }
                    });
                    sc.register(selector, SelectionKey.OP_READ);
                } else {
                    System.exit(1); // 连接失败，进程退出
                }
            }

            if (key.isReadable()) {
                ByteBuffer readBuffer = ByteBuffer.allocate(1024);
                int readBytes = sc.read(readBuffer);
                if (readBytes > 0) {
                    readBuffer.flip();
                    byte[] bytes = new byte[readBuffer.remaining()];
                    readBuffer.get(bytes);
                    String body = new String(bytes, "UTF-8");
                    System.out.println(body);

                    if (body.equals("Quit")) {
                        this.stop = true;
                    }
                } else if (readBytes < 0) {
                    // 对端链路关闭
                    key.cancel();
                    sc.close();
                } else
                    ; // 读到0字节，忽略
            }

            if (key.isWritable()) {
                System.out.println("The key is writable");
            }
        }
    }


    private void doWrite(SocketChannel sc) throws IOException {
/*		System.out.println("请输入消息[输入\"Quit\"]退出：");
		BufferedReader stdIn = new BufferedReader(new InputStreamReader(
				System.in));
		String userInput;

		while ((userInput = stdIn.readLine()) != null) {
			out.println(userInput);
			System.out.println(in.readLine());*/
        byte[] req = "QUERY TIME ORDER".getBytes();
        ByteBuffer writeBuffer = ByteBuffer.allocate(req.length);
        writeBuffer.put(req);
        writeBuffer.flip();
        sc.write(writeBuffer);
        if (!writeBuffer.hasRemaining())
            System.out.println("Send order 2 server succeed.");

/*			
			if (userInput.equals("Quit")) {
				System.out.println("Closing client");
				out.close();
				in.close();
				stdIn.close();
				echoSocket.close();
				System.exit(1);
			}
			System.out.println("请输入消息[输入\"Quit\"]退出：");

		}*/


    }
}